1. Field of the Invention
This invention relates to electronic imaging apparatus and, more particularly, to electronic imaging apparatus in which exposure is controlled in accordance with the output of an image pickup element, and a drive device for the image pickup element.
2. Description of the Related Art
The conventional electronic imaging apparatuses have employed either one of the two exposure control methods of which the first is to derive the light value not from the image pickup element but from another element solely used therefor, and the second is by utilizing the output of the image pickup element. In the first method, because the image pickup and light metering elements have different characteristics from each other and because the light arrangements to both elements are different from each other, an error occurs. Hence there was a problem that a high accuracy of exposure control could not be assured.
In the second method also, because the image pickup elements generally have a narrow dynamic range of operation, a problem arose that, for example, when a servo intervened between in that element and the exposure control means, the time until the exposure control is complete became very long.
To overcome these problems, attempts have been made to use both of the aforesaid first and second methods, as, for example, disclosed in Japanese Laid-Open Patent Application No. Sho 59-194574.
At this level of technique, however, though the exposure control time becomes shorter than in the second method, there is many a photographic situation where much shorter a time is required.
Also, in landscape photography, for example, with a person ordinarily framed when in shooting, because the output of the image pickup element included a large proportion of the light amount from, for example, the bright sky or the like in the background, the derived light value was dim for the person and an under-exposure resulted over the entire area of the frame.
Such a problem was commonly encountered even in the imaging apparatus where the output of the image pickup element was processed for purposes other than the light metering one.